A stupid creature will harass you for no reason, for no advantage, without any plan or scheme and at the most improbable times and places. You have no rational way of telling if and when and how and why the stupid creature attacks. When confronted with a stupid individual you are completely at his mercy. Because the stupid person’s actions do not conform to the rules of rationality, it follows that:

a) one is generally caught by surprise by the attack; b) even when one becomes aware of the attack, one cannot organize a rational defense, because the attack itself lacks any rational structure.

The fact that the activity and movements of a stupid creature are absolutely erratic and irrational not only makes defense problematic but it also makes any counter-attack extremely difficult – like trying to shoot at an object which is capable of the most improbable and unimaginable movements. This is what both Dickens and Schiller had in mind when the former stated that “with stupidity and sound digestion man may front much” and the latter wrote that “against stupidity the very Gods fight in vain.”

via The Basic Laws of Human Stupidity.